Curing and drying apparatus



June ll, 1968 B. J. PERRY, JR 3,387,387

CURING AND DRYING APPARATUS Filed NOV. I5, 1967 HUI 26 m INVENTOR BRYAN J. PERRY ,JR

ATTDRNEY United States Patent O 3,387,387 CURING AND DRYING APPARATUS Bryan J. Perry, .'ir., Greenville, S.C., assignor t0 Kitchen & Perry, Inc., Greenville, S.C., a corporation of South Carolina Continuation-impart of application Ser. No. 491,216,

Sept. 29, 1965. This application Nov. 3, 1967, Ser.

Claims. (Cl. 34-208) ABSTRACT UF THE DISCLOSURE An apparatus for the curing or drying of free-hanging moving articles in a zone where uniform temperature is maintained in all parts of the zone along with continuous recirculation of heated air. An elevated curing or heating chamber assures natural entrapment of heated air without the necessity for closures or seals and with only the minimum requirement for exhaust to maintain safety.

Cross-reference to related application This application is a continuation in part of copending application Ser. No. 491,216, led Sept. 29, 1965, now Patent No. 3,358,386, for Curing Apparatus for Press- Free Garments and the Like.

Background of the invention The invention is concerned with the curing or `drying of articles, such as articles containing urea formaldehyde and like resins. Such articles must -be cured at a very uniform temperature for satisfactory results, Certain other types of articles to be dried or cured also require a constant ternperature and the invention apparatus satisfies this need while providing for relatively high speed operation and high capacity with great economy. The invention is also an improvement and simplification of the apparatus covered in the above prior application.

In general, the prior art has provided two classes of ovens employed for the purposes of the invention. One type, the batch type, provides a chamber with a door closure into which the articles to be dried or cured are rolled on racks, after which the door is closed for a given time period, and nally the door is re-opened and the dried or cured articles are removed. This type of oven is essentially a low capacity type and slow to operate requiring considerable hand labor for loading and unloading. A second conventional type is the open end conveyor type oven which utilizes a moving conveyor to transport articles into and out of a heating zone. Generally, there is no way to prevent the escape of hot air through the open ends of the oven and consequently the required uniform temperature is almost impossible to maintain. Also, a high capacity exhaust system is required. For this type of apparatus to be successful, a much longer heating zone is required to achieve a section of nearly uniform temperature and this results in poor economy and a using of much floor space. The present invention completely overcomes all of these prior art difficulties and fully achieves the stated requirements of the art in a highly economical and eicient manner, as will become apparent.

Summary of the invention The invention utilizes a horizontally elongated elevated heating or oven chamber into which an article conveyor extends through a bottom opening at one end of the chamber, The opposite end of the heating chamber is above a small depressed compartment which houses air heating and air circulating means. A pair of compact corner `ducts rise through one end of the heating chamber ICC and convey hot air to an overhead shallow plenum equipped with adjustable grills which direct the hot air in a manner to achieve temperature uniformity throughout the length of the heating chamber. The floor of the heating chamber constitutes the upper Wall of a shallow lower plenum which receives the return air through an arrangement of grills and the lower plenum leads back to the de pressed compartment containing the heating means.

Briefidescriplion of the drawing FIGURE 1 is a partly diagrammatic horizontal section through the apparatus taken on line 1 1 of FIGURE 2;

FGURE 2 is a longitudinal vertical section taken on line 2-2 of FIGURE l;

FIGURE 3 is a transverse vertical section, partly in elevation, taken on line 3 3 of FIGURE 2; and

FIGURE 4 is a vertical section taken on line 4-4 of FIGURE 2.

Description of the preferred embodiment Referring to the drawings wherein like numerals designate like parts throughout the same, the numeral 10 designates generally a horizontally elongated rectangular oven housing including a top wall 11, vertical side walls 12, an end wall 13 and a partial end wall 14 at the entrance end of the oven. A large entrance opening 15 exists below the partial end wall 14 for the ingress and egress of the articles to be cured or dried by the apparatus. The oven addition ally vcomprises a somewhat elevated bottom wall or floor section 16 terminating at the opening 15 and joined with a vertical wall 17, in turn leading to a oor 18 connecting with the end wall 13. The side walls 12 extend downwardly to the floor 18 at the region of this lioor section, and a depressed chamber 19 is formed to receive apparatus components to be described. The enumerated wall sections of the oven 1()` are preferably heat insulated in a conventional manner and the supporting structure of the oven, not shown, may be entirely conventional and forms no part of the invention.

A conventional article conveyor 20 is utilized to convey suspended articles continuously into and out of the oven structure via the opening 15. The articles, not shown, may be a variety of articles requiring curing or drying at a very uniform elevated temperature. The conveyor structure shown diagrammatically embodies a supporting track for a power driven conveyor chain 21 or the like, said track including a short inclined portion 22 leading through the top of the opening 15 from the exterior of the oven, and leading into an elevated horizontal long track or conveyor section 23 near and below the top wall 11. As disclosed in said prior application, the conveyor forms an endless horizontal loop in the upper portion of the main elongated heating chamber 24 of the apparatus so that various articles may be moved continuously at the desired speed into and out of the apparatus while suspended from the chain 21 or like means. The conveyor structure 20 may be substantially identical to that disclosed in said prior application and per se is conventional and need not be described in great detail herein for a proper understanding of the invention.

Within the depressed compartment 19 centrally thereof is an air heater 25, such as an electric, gas, oil, or steamoperated heater. A horizontal wall or panel 26 immediately above the wall 16 forms a shallow lower plenum 27 leading to the compartment 19 at the return side of the heater 2S, there being appropriate baies 28 and 29 to assure passage of the return air to the return side of the heater. As shown, a plurality of spaced grills 30 for the return air are mounted in the horizontal wall 26 preferably in longitudinal and transverse rows. These grills preferably contain adjustable air-directing louvers or like means.

Mounted in compartment 19 on the opposite side of the heater 25 and spaced therefrom is a blower 31 consisting only of a biaded blower wheel and suitable drive motor means 32, and without the usual exponential curve scroll surrounding the same. Instead, the blower wheel 31 is simply housed in a rectangular box formed by a vertical wall 331 in the compartment 19 and a top wall 34 at the elevation of the wall 26, there being an inlet 35 to the blower facing the heater 25. This is a simplified construction which is very compact and also eiiicient.

A pair of triangular cross section ducts 36 formed by diagonal plates 37 rise from the blower wheel box at the two adjacent corners of the oven shown clearly in FIG- URES 1 and 2. The bottoms of the ducts or passages 36 simply open through the wall 34 and thus receive the air fed upwardly by the blower wheel in a uniform and equal manner. The triangular ducts 36 direct the hot air to an overhead shallow horizontal plenum 38 immediately below the wall 11 and extending for the full length of the main heating chamber 24. The plenum space 38 is defined by horizontal panel 39 spaced below the wall 11, including an end closure 40. The panel 39 also has a plurality of adjustable grills 41 mounted therein in the same manner described for the panel 26 for the purpose of directing the hot air downwardly into the main chamber 24. In this connection, as approximately indicated =by the air iiow arrows in FIGURE 2, the grills may have their louvers adjusted so that more air will be pumped toward the entrance end of the chamber 24 than toward the rear closed end, thus osetting any tendency for the temperature to drop adjacent the opening and maintaining a uniform temperature and circulation throughout the entire main chamber. Additionally, there is no natural tendency for cold air to enter the elevated heating chamber 24 through the lower entrance opening 15.

Preferably, at the end of the apparatus remote from the heating means 25, a conventional low capacity exhaust means 42 is mounted on the wall 14 primarily for the purpose of maintaining safety. Actually, there is little necessity for exhaust in the normal operation of the apparatus.

Operation Articles suspended on the moving conveyor element 21 are conveyed continuously into and out of the main chamber 24. The speed of movement can be regulated by conventional means to achieve the desired time of drying or curing. The exhaust means 42 can be operated intermittently to further aid in maintaining uniform temperature.

With the heater 25 and blower wheel 31 in continuous operation, hot air is forced upwardly through the corner triangular ducts 36 to the upper plenum 38 and downwardly through the several grills 41 to the main heating chamber 24. As explained, the grills 41 can be adjusted to maintain uniformity of temperature throughout the length of the chamber 24. Finally, the air returns through the grills 30 to the lower plenum 27 and the return side of the heater 25.

The construction is most compact and simplified and no widening of the oven is required to accommodate the ducts 36 or the apparatus components 25 and 31. The

advantages of the invention should be apparent to those skilled in the art in light of the description.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.

I claim:

1. A curing and drying apparatus comprising a horizontally elongated oven housing including an elevated horizontally elongated main chamber, said housing having an end opening for the ingress and egress of articles at an elevation below the main chamber, an article conveyor loop extending through the main chamber horizontally near the top thereof and having a portion leading through said end ingress and egress opening, an upper plenum space at the top of the main chamber substantially coextensive in horizontal area therewith, a lower plenum space at the bottom of the main chamber substantially coextensive in horizontal area therewith, air directing grills connected with the upper and lower plenum spaces, a depressed compartment beneath the end portion of the main chamber remote from the ingress and egress opening and in communication with the lower plenum space, corner vertical ducts rising from said compartment at the adjacent corners of the oven housing and communicating with the upper plenum space, and forced draft heating means in the depressed compartment operable to continuously circulate hot air upwardly through said ducts.

2. A curing and drying apparatus according to claim 1, and a vertical divider wall in the depressed compartment forming with other adjacent walls of the apparatus a blower wheel box, the lower ends of the corner vertical ducts communicating with the top of said box at the opposite sides thereof, an unhoused blower wheel within the box having an inlet within the depressed compartment, and a heating unit in the depressed compartment in opposed relation to the blower wheel.

3. A curing and drying apparatus according to claim y1, wherein the corner ducts are triangular in cross section and are formed by corners of the oven housing and diagonal plates extending across said corners.

4. A curing and drying apparatus according to claim 1, and wherein said upper and lower plenum spaces are Vertically shallow in comparison to the height of the main chamber and are defined by horizontal partitions spaced below and above the top and bottom walls, respectively, of the main chamber.

5. A curing and drying apparatus according to claim 4, and wherein said `grills are mounted in spaced relation in said horizontal partitions which deiine said upper and lower plenum spaces.

References Cited UNITED STATES PATENTS 1,761,472 5/1930 Fox 34-207 2,100,838 11/1937 De Vout 34-208 XR 3,257,739 6/ 1966 Wentz.

3,358,386 12/1967 Perry 34-208 FREDERICK L. MATTESON, IR., Primary Examiner. A. D. HERRMANN, Assistant Examiner. 

